The engine immobiliser system is designed to prevent the vehicle from being stolen. This system uses a transponder key ecu that stores the key codes of authorized ignition keys. If an attempt is made to start the engine using an unauthorized key, the ecu sends a signal to the ecm to prohibit fuel delivery and ignition, effectively disabling the engine.

The transponder key coil receives this signal, the transponder key amplifier amplifies it, and then the signal is transmitted to the ecu. The ecu matches the key's id code with the vehicle's id code, which was previously registered in the ecu and then communicates the results to the ecm using sfi communication.
Engine immobiliser system
How to proceed with troubleshootingIf a warning light turns
on or a warning buzzer
sounds
Calmly perform the following actions if any of the warning lights
comes on or flashes. If a light comes on or flashes, but then
goes off, this does not necessarily indicate a malfunction in the
system. However, if this continues to occur, have the vehicle
inspected by your toyota dealer.
Stop t ...
System description
System description
Hint:
The skid control ecu forms a single unit with the abs
and traction actuator.
Abs (anti-lock brake system):
the abs helps prevent the wheels from locking
when the brakes are applied firmly or on a slippery
surface.
Operation description:
the skid ...
Evaporative emission control system incorrect purge flow
Dtc summary
Description
The description can be found in the evap (evaporative emission) system (see
page es-335).
Inspection procedure
Refer to the evap system (see page es-340).
Monitor description
The two monitors, key-off and purge flow, are used to detect malfunctions
relating ...